Fire alarm



March 18, 1969 T. J. COLLUM 3,434,133

FIRE ALARM Filed April 27. 1966 Sheet of 2 INVENTOR. TH EODORE J. COLLUM MAHON EY, MILLER & RAMBO momxsvs United States Patent 4 Claims ABSTRACT OF THE DISCLOSURE A simple, compact, self-contained fire alarm device having its own source of current which is in the form of a reserve-type primary battery that is activated upon the addition of an electrolyte which occurs only upon the predetermined increase of the ambient temperature.

The present invention is an improvement over that disclosed in my Patent No. 2,989,737, issued June 20, 1961.

As stated in the patent, previously proposed have been fire alarm systems employing an electrically operable alarm which is actuated in response to the application of heat to a heat-responsive element or device. Of the commercially available alarms and systems, wired systems are more highly rated by fire protective and insurance associations. Unless automatically recharged batteries are a part of a system, it can fail if commercial current fails during a confiagration. Although wired systems are widely used in large properties, such as commercial buildings, apartments, hotels, and the like, such systems, however, are generally not popular in smaller properties, even small commercial buildings, and especially in duplex or single residential properties.

Other type alarms which are approved by fire protective and insurance associations are those releasing a gas being held under pressure, thereby sounding a horn--as distinguished from an electrically operable alarm. Although single units are used in some commercial or residential properties, to combine such units into a system requires connecting tubing more complicated and less reliable than the wiring of electrical systems. Neither single units nor systems have become popular, especially in small properties.

The owners of small properties are not sufficiently impressed with the need to install fire alarm systems of any kind at the time of construction, for the reason that such systems, whether electrical or using inert gas, are expensive in both initial cost and installation, usually by highly skilled craftsmen. They are even more difficult and expensive to install after the building or finishing has been completed; this is especially true for a system using tubing.

Fire alarms which have been previously proposed to avoid the expense inherent to the systems or alarms described above generally have as their source of electrical current one or more dry cell batteries. Such batteries are subject to deterioration in a relatively short time. The frequent inspection and replacement of batteries is such a burden that, in time, carelessness in inspection and replacement is likely to occur. If the batteries deteriorate, the system becomes worthless.

An objective of the present invention, as with the invention disclosed and claimed in said patent, i to provide a fire alarm device which is installed with ease and facility in most buildings, including both small commercial buildings and residences, either during or after construction, using relatively unskilled labor and thereby low in cost; one employing a power unit that is a reserve-type battery, having virtually indefinite life with no dependence upon commercial current, using principles already proven in submarine torpedo guidance and splashdowns of orbiting missiles, requiring no inspection to verify the electrical potential, and one which is therefore highly reliable and elfective in action.

Another objective of the present invention, as with the patented invention, is to provideby using selfcontained power units of sutficient outputa fire alarm device which can be similarly installed with ease and facility, whereby by connecting several devices to a centrally located alarm, such central alarm may be made of sound, in addition to the alarm on the device at the point of the conflagration.

Another objective is to provide a fire alarm device which-by its designis most likely to be installed in a ceiling, where heat increases more rapidly than elsewhere in a room, thereby providing more rapid response to a confiagration. It may, however, be installed horizontally in a wall, or in either position by use of mounting devices.

A further objective is to provide a fire alarm device which would be pleasing in decor, relatively inconspicuous in either commercial or residential properties, somewhat resembling apertures currently provided for air conditioning, ceiling lights, and the like.

These and other objectives and advantages of this more advanced design will be fully apparent wit-h the following description when taken in conjunction with the annexed drawings, in which:

FIGURE 1 is an isometric view of the device of the present invention as viewed from the side and slightly below.

FIGURE 2 is a vertical or axial sectional view taken on the line 2-2 of FIGURE 1.

FIGURE 3 is a detail in perspective of the battery activating mechanism.

FIGURE 4 is a view similar to FIGURE 2 but at a right angle thereto on the line 4-4 of FIGURE 5.

FIGURE 5 is a horizontal or transverse sectional view taken on line 5-5 of FIGURE 4.

FIGURE 6 is a schematic sectional view showing a modification of the electrolyte container.

With particular reference to the drawings, it will be noted in FIGURE 1 that the complete fire alarm device of this invention is shown. It preferably includes a tubular main case or shell 10 of annular cross-section which is carried by a mounting collar 11 of annular form, and preferably of metal or plastic and lined with a thermal insulating liner 12, which surrounds its lower open end as indicated more clearly in FIGURE 2. The collar 11 may be mounted in a small hole in the ceiling C, which can be readily bored, or it may be fastened to a wall or other vertical surface by a mounting bracket (not shown). The lower end of the case 10 telescopes into the liner 12 of the collar 11 and is provided with radially projecting lugs 13 (FIGURE 5) spaced upwardly from its lower end. These lugs will engage and rest on the upper edge of the radially projecting lugs 14 formed on the upper edge of the collar 11 to support the case 10 therefrom. As indicated, the liner 12 or the collar 11 is of a suitable thermal insulating material so as to insulate the room below from the space above. The collar liner 12 will be recessed upwardly slightly relative to the surrounding collar 11 which is flush with the exposed ceiling surface to receive a perforated cover plate 15 which will engage the lower edge of the collar liner and will be secured thereto by a mastic or by other suitable means so that it will be flush with the ceiling surface.

Mounted within the lower open end of the case 10 is an inverted cup-like member 16 which is of metal and of annular cross-section and is of smaller diameter than the case so that an annular vertically extending space 17 is formed therearound. This space is sealed at its lower end by means of an outwardly projecting flange 18 which extends beneath the case and may be secured thereto by a sealing mastic. The flange 18 has a spacer 19 depending therefrom which may contact the cover plate at its inner or upper surface.

The inverted cup-like member 16 not only serves to seal the lower end of the case 10 to make it fluid tiglit but also serves to provide a downwardly opening charnher for receiving a buzzer or other electrically-activated signaling device. This buzzer 20 may be provided with a peripheral lip 20a which engages the member 16' at the flange 18 to limit upward telescoping therein and may rest on the removable cover plate 15. This buzzer 20 has leads 21 and 22 leading into it from the top and coming from a battery.

This battery is of the deferred action type and preferably includes plates such as silver chloride and magnesium. These plates are indicated at 23 and 24 and, as shown in FIGURE 5, are of arcuate form and extend vertically in the case 10 adjacent the wall thereof, their lower portions being disposed in the annular chamber 17 and their lower extremities resting on the flange 18 of the member 16. Produced under quality control, these plates should last indefinitely and not be activated until subjected to a proper electrolyte. This is a commonly recognized and used type of battery. The two sets of plates of the battery are connected in parallel by a double line 25 (FIGURE 5) and one lead 26 runs from the one set of the battery plates 23 to the lead 22 of the buzzer 20. This set of battery plates is also connected to a lead terminal 27 by a lead 28 which has a diode 29 connected therein. Also connected to these plates is a test terminal 30 which has an exposed extremity 31 at the lower surface of the cover plate 15. Circular nuts 30a screw onto the terminals 30 up into recesses in the cover 15, in which they are free to rotate, and engage the cover around the recesses to support the cover in place. Similarly, the other set of battery plates 24 is connected by a lead 32 to the buzzer lead 21 and to a test terminal 33 which has an exposed tip 34. A lead terminal 35 is also connected to these plates by means of a line 36. The exposed lead terminals 27 and 35 are above the case 10 and can be used in connecting a number of these alarm devices in parallel so that they could be in different locations in the building, connected to a master buzzer or signal. The diode 29 of each would protect the buzzer of that unit from being engaged when the battery of any other unit is activated, along with the master signal, thereby keeping low the output requirement of each unit.

The top wall 37 of the member 16 serves as a base for mounting the mechanism for releasing the liquid electrolyte which is disposed in an electrolyte container 40 which may be of thin plastic. This container 40 is of substantially cylindrical form and in the example shown has a slightly downwardly dished bottom 41 which includes a rupturable section 42 that ordinarily is connected on the bottom along a score line 43 of annular form. Thus, the bottom is downwardly convex with a removable central section. The container 40 telescopes into the upper end of the shell 10 and is provided with an outwardly projecting flange 44 intermediate its height which rests on an inturned support flange 45 on the upper end of the shell 10. It will be noted from FIGURE 4 that portions of the terminals 27 and 35 extend upwardly through aligning openings 39 in the flanges 44 and 45. The container 40 will be supplied with a suitable liquid electrolyte E which may be in the form of saltwater. A removable sealing cap or cover 46 is preferably disposed on the upper open end of the container 40 and this cap has a central inner plug section 46a which telescopes within the upper end of the container and an outer annular depending skirt 48 which slides downwardly over the outer surface of the container at its upper end. A fluid-tight seal is thus provided between the cap 46 and upper end of the container 40 and, in addition, a chamber 47 is provided in the cap .4 above the electrolyte to permit expansion of the electrolyte. Instead of a removable cap 46, the upper end of the container 40 may be permanently sealed after filling.

The mechanism for releasing the electrolyte comprises spring-actuated mechanism for striking the section 42 of the bottom of the container 40 to rupture the bottom. This means comprises a spring lever 50 made of wire bent into U-form or other suitable shape and which includes a spring coil 51 that surrounds a transverse pin or bolt 52 carried by the lugs 53 upstanding from the wall 37. A trigger 55 normally holds the lever 50 downwardly adjacent the wall 37 but can be actuated to release it so it will swing upwardly with considerable force to strike the bottom of the container 40 and rupture the section 42 therefrom. The trigger 55 is mounted for vertical swinging movement by a transverse pin or bolt 56 whose axis is parallel to that of the pin 52. In holding the lever 50 down, the end of the trigger will extend over the closed end of the lever and will be pulled downwardly by a flexible line 58 to prevent upward swinging of the lever. This line 58 will extend downwardly through the space 17 and its lower end will be anchored by fusible metal or alloy 57 poured into the lower end of a tubular pocket formed in one of the spacers 19 of the member 16. This metal or alloy will be exposed, at a point substantially flush with the cap 15, to the temperature of the room below the ceiling.

In manufacture, the collar 11 and liner 12, as well as the cap 15, would not be attached to the remainder of the assembly and would be used for ceiling mounting only. The electrolyte E could be added by the manufacturer or by the installer just before installation, after which the cover 46 would be mounted therein in sealing position. The rest of the assembly would be assembled as indicated providing a hermetically sealed battery chamber. In the assembly process, to prevent battery deterioration the air in the battery chamber should be made quite dry, either by assembling in a dry atmosphere or by exhausting normal air and adding dry air, for example, through the terminal passage openings 39 which are later sealed. It will be understood that the openings through which the test terminals 30 and 33 pass are previously sealed.

In installing in a ceiling, a suitable size bore is made. The collar 11 is then fastened in the bore without the liner 12. The buzzer is tested by applying external voltage across the test terminals tips 31 and 34. The assembly, with the lugs 13 angularly displaced from the lugs 14, is then lifted upwardly through the collar 11 which is of suflicient diameter to permit upward passage of the assembled cap 46, container 40, and case 10. When the assembly reaches the proper level, the case 10 is turned to move the outwardly projecting supporting lugs 13 thereof over the inwardly projecting lugs 14 of the collar 11. The entire assembly will thus be supported in place and the liner 12 and cover 15 may then be positioned as indicated. To remove the assembly, it is merely necessary to remove the cap and liner, turn the case 10 to displace the lugs 13 from the lugs 14 and allow the assembly to drop.

In activation of the alarm device, upon the development of a sufliciently high temperature in the room in the ceiling of which it is disposed, the fusible metal or alloy 57 will be melted. This will release the trigger 55 and permit the spring 51 to swing the lever arm 50 upwardly. The closed end of the lever will strike the section 42 and rupture it upwardly into the container thereby releasing the electrolyte E and allowing it to flow down into contact with the battery plates thereby activating the battery. This will sound the buzzer 20 and activate any central alarm if the device is part of a system.

In FIGURE 6, there is illustrated a modification of the electrolyte container which will facilitate rupturing thereof. In this case the bottom section 42a of the container 40a is provided with a depending projection 60. The closed end of the lever 50, when the lever is released, will strike this projection and exert a twisting action which will more readily rupture the bottom of the container.

It will be apparent from the above that the device of this invention is of overall cylindrical form and can be mounted in a ceiling by simply mounting the supporting collar therein by disposing it in a bored hole. The various elements of the assembly are compactly enclosed in the outer shell and the device is therefore relatively small which facilitates mounting. The main assembly, as shown, can be inserted in the ceiling, or be removed therefrom after activating for renewal, by simple axial and twisting movements, or it could be mounted by other means, such as support brackets. The simple spring-actuated lever mechanism is an effective means for rupturing the bottom of the electrolyte container to release the electrolyte for activating the battery, especially since the spring-actuated lever directly strikes the bottom of the container. Also, since this mechanism is enclosed in a sealed chamber it will not be subject to corrosion. Also, the use of the fusible .alloy or metal, exposed at the ceiling surface, makes the device very sensitive to high temperatures. The assembly is such that after removal, the electrolyte can be readily replenished.

When several of the devices are connected in a system, the use of the diodes, as described, prevents reverse current flow so that the location of the high temperature can be pin-pointed and keeps low the output requirement of each unit. Although the device is particularly suitable for mounting in a ceiling where it will be most effective, it can be mounted in other locations as well.

Having thus described this invention, what is claimed is:

1. A fire alarm device comprising a case having a battery chamber with battery plates disposed therein that are connected to a signaling means, said plates being of a nature to be activated when subjected to an electrolyte, a separate chamber containing the electrolyte and having a ruptu-rable wall which, when ruptured, will allow the electrolyte to enter said battery chamber into contact with the plates to activate the plates to produce an electric current to thereby actuate said signaling means, means for rupturing said wall, said means comprising a member adapted to contact directly with said wall, said member being provided with a spring which biases it toward wallcontacting position with rupturing force, a trigger normally holding said member in an inoperatve position away from said wall, trigger-releasing means actuated by an increase in ambient temperature for releasing the trigger to, in turn, release said member and permit it to strike said Wall and rupture it and thereby supply the electrolyte to said battery plates, said case being of annular tubular form to facilitate mounting, an annular mounting collar in which said case telescopes, said mounting collar having radially inwardly extending support lugs, and said case having radially outwardly extending support lugs adapted to be angularly aligned with or displaced from the support lugs on the collar by rotation of the case relative to the collar.

2. A fire alarm device comprising a case having a battery chamber with battery plates disposed therein that are connected to a signaling means, said plates being of a nature to be activated when subjected to an electrolyte, a separate chamber containing the electrolyte and having a rupturable wall which, when ruptured, will allow the electrolyte to enter said battery chamber into contact with the plates to activate the plates to produce an electric current to thereby actuate said signaling means, means for rupturing said wall, said means comprising a member adapted to contact directly with said wall, said member being provided with a spring which biases it toward wallcontacting position with rupturing force, a trigger normally holding said member in an inoperative position away from said wall, trigger-releasing means actuated by an increase in ambient temperature for releasing the trigger to, in turn, release said member and permit it to strike said wall and rupture it and thereby supply the electrolyte to said battery plates, said case being of annular tubular form, with the battery chamber in the lower portion thereof, said signaling means being disposed in a downwardly opening chamber provided by means of an inverted annular cup inserted in the lower end of the case and sealed therein to provide an annular space around the cup within the lower portion of the case, said battery plates extending downwardly into said space.

3. A fire alarm device according to claim 2 in which said case is also open at its upper end, said electrolyte chamber being provided by a cup telescoped within the upper end of the case, said cup having a weakened bottom with which said lever, when released strikes.

4. A fire alarm device according to claim 3 having a removable cap on said electrolyte cup.

References Cited UNITED STATES PATENTS 4/1963 Mauer et al. 340-213 6/ 1967 Edwards et a1 340227.1

U.S. Cl. X.R. 136-162 

